[alsa-devel] Spam in the wiki

I got a notification, because a wiki page that I had created was edited by a spammer. Looking at the recent changes, it seems that there's quite a lot of spam activity: http://www.alsa-project.org/main/index.php/Special:RecentChanges

Can the wiki user registrations be restricted? There's already a captcha, but that doesn't seem very effective.

--  Tanu